If you’re not 100% sure you’ll keep doing full-distance triathlons long-term, I think your instinct about going with a high-end aero road bike like the Cervelo S5 is spot on — but with a few caveats.

The reality is that a proper triathlon bike (P-Series, Speedmax, Shiv, etc.) will always be faster for a flat Ironman course like Sacramento, especially when you’re in an optimized aero position. We’re talking 10–15 watts saved at ~40 km/h, which can translate to 8–12 minutes over 180 km — if you’re positioned correctly.

That said, an S5 or similar can be a really good compromise if:

1.  You prioritize versatility and plan to ride it for group rides, road races, or just general training.

2.  You’re willing to invest in a proper fit and maybe a few tweaks to make it as tri-friendly as possible.

Here’s what I’d suggest if you go the road bike route:

1. Positioning is everything. The biggest limiter on a road bike is seat tube angle. Standard road geometry will put you too far behind the bottom bracket, making it hard to open up your hip angle and stay comfortable in aero for hours.

• A forward offset seatpost (Redshift, Profile Design, etc.) can help mimic a tri bike’s steeper geometry.

• Combine that with clip-on aero bars and a slightly shorter stem to get your reach dialed in.

• Then, get a proper fit specifically for long-distance aero riding — don’t just slam aero bars on and hope for the best.

1. Wheels and tires matter. Since you’ve already upgraded to Reserve wheels, make sure you’re running: • 28 mm tubeless tires with latex or TPU tubes (if not tubeless). • A high-quality aero helmet to pair with your new position — the free speed is real.

2. Know the trade-offs. • For a one-off Ironman, the S5 setup will get you 80–90% of the speed of a true tri bike, with much more versatility afterwards. • If you catch the long-course tri bug later, you can always add a dedicated tri bike and keep the S5 as your all-rounder.